Dental materials, particularly dental impression materials, are often provided as two- or multi-component materials that are separately stored but mixed together just before use. In recent years, devices have been developed which provide for automatic mixing and dispensing of two-component dental materials. An exemplary device for mixing and dispensing a dental impression material is for example available under the designation 3M™ ESPE™ Pentamix™ from 3M ESPE AG, Germany. Appropriate packages have been developed which contain the individual components of the material and allow the dental materials to be dispensed from such a mixing and dispensing device.
Typically the material components are simultaneously supplied from such a package through a mixer. The mixer typically mixes continuously supplied components as they flow through the mixer, and provides the mixture from an outlet. Some mixing and dispensing devices are configured for dynamically mixing of the components. Appropriate mixers typically have a moving part, for example a mixing rotor, for actively agitating the components while they are supplied through the mixer.
The mixed components in many cases are adapted to chemically react with one another to form a hardenable material. A used mixer may therefore be blocked by the hardened material a time after the mixing and dispensing is discontinued. Therefore mixers used with mixing and dispensing devices as mentioned are therefore generally exchangeable and often disposable parts. Dentists and their assistants may have to remove and replace mixers several times each day.
An example of a mixing and dispensing device and a dynamic mixer is disclosed in WO 2007/106701. The device has a drive shaft for driving a mixer. The mixer is placeable on the drive shaft in two positions to facilitate placement of the mixer on the drive shaft.
EP1458467 discloses a device for mixing of two components to form a dental compound. The device has a mixer with inlet receptacles for the components and an outlet receptacle for the mixed compound. The device also has a mixing element that is disposed in the mixer and propelled around a longitudinal axis. The mixer has a coupling section with two coupling receptacles for connecting with two dispensing openings of a device for dispensing the two paste-like compounds. The mixer further has a coupling receptacle for coupling with a driving bar of the device.
Although a variety of different mixing and dispensing device and mixers are on the market there is still a need for solutions that helps providing improved handling for a user, and that are relatively inexpensive.